Semiconductor device and method for manufacturing the same

ABSTRACT

A resin sealed type semiconductor device, is provided with a semiconductor chip which has a pad formed on a main surface thereof, an insulating film which is formed on a part of the pad and on the main surface of the semiconductor chip, an interconnection which is formed on a part of the insulating film and which is electrically connected to the pad, a sealing resin which seals the interconnection and the insulating film, a post formed on the interconnection which has a surface exposed to outside of the sealing resin which is electrically connected to the interconnection, a bump electrode which is mounted on the exposed surface of the post and a radiation post which is formed on the insulating film and which has a surface exposed to outside of the sealing resin.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention generally relates to technology for manufacturing a semiconductor device, and more particularly, to a semiconductor device which has the improved radiation efficiency and a method for manufacturing the semiconductor device.

[0003] This application is a counterpart of Japanese patent application, Serial Number 104732/2000, filed Apr. 6, 2000, the subject matter of which is incorporated herein by reference.

[0004] 2. Description of the Related Art

[0005] Recently, spread of the mobile terminal has been accelerated toward smaller, thinner and lighter mobile terminal. In order to achieve compactness, effort has been made to reduce the size of the semiconductor device mounted on the mobile terminal. Such efforts are focused on the development of semiconductor devices having a semiconductor package in the size of a chip referred to as Chip Size Package (hereinafter CSP).

[0006] The size of CSP is substantially the same as that of the chip or slightly large as that of the CSP. There is the resin sealed type semiconductor device which is referred to as Wafer Level Chip Size Package/Wafer Level Chip Scale Package (hereinafter W-CSP) among CSP. The size of W-CSP is the same as that of the chip.

[0007] The conventional CSP type semiconductor device will be described with reference to FIGS. 12-14.

[0008]FIG. 12 is an entire perspective view showing a wafer and the conventional resin sealed type semiconductor device taken by dicing the wafer. FIG. 13 is a cross sectional view taken line A-A of the semiconductor device shown in FIG. 12. As shown in FIG. 13, the conventional resin sealed type semiconductor device comprises a semiconductor chip 1301, a post 1302, a solder bump 130, a re-tribute 1304, a sealing resin 1305, a pad 1306 and an insulating film 1307. The semiconductor chip 1301 has a main surface 1301 a in which a circuit, e.g. a transistor etc is formed. The pad 1306 which is an aluminum pad, is formed on the main surface 1301 a of the semiconductor chip 1301. The insulating film 1307 is formed on the main surface 1301 a of the semiconductor chip 1301. The re-tribute 1304 is formed on the insulating film 1307 and the main surface 1301 a of the semiconductor chip 1301, and is electrically connected to the pad 1306 and the post 1302. The re-tribute 1304 functions as an interconnection, which is made of copper. The post 1302 which is made of copper, is formed on the re-tribute 1304. The solder bump 1303 is mounted on upper surface of the post 1302, and is electrically connected to the post 1302. The solder bump 1303 is a spherical electrode, which is made of copper. The sealing resin 1305 seals the insulating film 1307, the re-tribute 1304 and the post 1302 except for the solder bump 1303. Now, due to an explanatory convenience, the number of the post 1302 etc is limited to one or two in the drawings.

[0009] Processes which include a process of mounting the solder bump 1303, are performed in a wafer state. After these processes are completed, the wafer is diced. Thereby, the conventional resin sealed type semiconductor device which is called as CSP, is obtained (refer to FIG. 13).

[0010] A radiation pass of the conventional resin sealed type semiconductor device will be described with reference to FIG. 14. As shown in FIG. 14, the conventional resin sealed type semiconductor device is mounted on a substrate 1401 via the solder bumps 1303. An arrow shown in FIG. 14 designates the radiation pass of the heat in case the heat is radiated from the semiconductor chip 1301 to outside of the semiconductor device. As shown in FIG. 14, the heat generated near the main surface 1301 a of the semiconductor chip 1301, is radiated via the posts 1302, the solder bumps 1303 and the substrate 1401.

[0011] However, the main surface 1301 a of the semiconductor chip 1301 is covered with the sealing resin 1305 which has a low thermal conductivity. Therefore, the radiation pass near the main surface 1301 a, is limited to the pass explained above. Consequently, the heat near the main surface is not enough radiated so that the demand is satisfied.

SUMMARY OF THE INVENTION

[0012] It is an object of the present invention to provide a resin sealed type semiconductor device that may improve radiation efficiency.

[0013] It is another object of the present invention to provide a method for making a semiconductor device that may reduce manufacturing costs.

[0014] It is still another object of the present invention to provide a method for making a semiconductor device that may reduce manufacturing steps.

[0015] It is further object of the present invention to provide a method of making a semiconductor device that may reduce a manufacturing time period.

[0016] According to one aspect of the present invention, for achieving the above object, there is provided a resin sealed type semiconductor device, is provided with a semiconductor chip having a pad which is formed on a main surface thereof, an insulating film formed on a part of the pad and on the main surface of the semiconductor chip, an interconnection formed on a part of the insulating film, being electrically connected to the pad, a sealing resin sealing the interconnection and the insulating film, a post unit formed on the insulating film, having an edge side exposed to outside of the sealing resin, being electrically connected to the interconnection, a bump formed on the exposed edge side of the post unit and a radiation post unit formed on the insulating film, having an edge side exposed to outside of the sealing resin.

[0017] The above and further objects and novel features of the invention will more fully appear from the following detailed description, appended claims and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 is a plane view showing a resin sealed type semiconductor device according to a first preferred embodiment of the present invention.

[0019]FIG. 2 is a cross sectional view showing a resin sealed type semiconductor device according to a first preferred embodiment of the present invention.

[0020]FIG. 3 is a cross sectional view showing the radiation paths of a resin sealed type semiconductor device according to a first preferred embodiment of the present invention.

[0021]FIG. 4(a) through FIG. 4(d) are process diagrams showing a method for manufacturing a resin sealed type semiconductor device according to first, second and third embodiments of the present invention.

[0022]FIG. 5(a) through FIG. 5(d) are process diagrams showing a method for manufacturing a resin sealed type semiconductor device according to first, second and third embodiments of the present invention.

[0023]FIG. 6 is a plane view showing a resin sealed type semiconductor device according to a second embodiment of the present invention.

[0024]FIG. 7 is a cross sectional view showing a resin sealed type semiconductor device according to a second embodiment of the present invention.

[0025]FIG. 8 is a cross sectional view showing radiation passs of a resin sealed type semiconductor device according to a second embodiment of the present invention.

[0026]FIG. 9 is a cross sectional view showing a resin sealed type semiconductor device according to a third embodiment of the present invention.

[0027]FIG. 10(a) through FIG. 10(e) are process diagrams showing a method for manufacturing a resin sealed type semiconductor device according to a third embodiment of the present invention.

[0028]FIG. 11(a) through FIG. 11(b) are plan showing an arrangement relationship between posts and radiation posts.

[0029]FIG. 12 is a perspective view showing relationship between a wafer and a resin sealed type semiconductor device.

[0030]FIG. 13 is a cross sectional view showing a structure of a resin sealed type semiconductor device of the related art.

[0031]FIG. 14 is a cross sectional view showing a radiation path of a resin sealed type semiconductor device of the related art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] In what follows, the present invention will be explained with embodiments of the present invention. However, the invention is not limited to the specific embodiments. Moreover, not all the combinations of the characteristics of the present invention described in the embodiments are essential to the problem solving means by the present invention.

[0033] (First Preferred Embodiment)

[0034] A resin sealed type semiconductor device according to a first preferred embodiment of the present invention will be described with reference to FIGS. 1-5.

[0035] Frist, the composition of the resin sealed type semiconductor device according to the first preferred embodiment will be described with reference to FIGS. 1-2. FIG. 1 is a plane view showing the resin sealed type semiconductor device having a wafer level chip size package structure individually divided from a wafer. FIG. 2 is a cross sectional view taken line B-B of the semiconductor device shown in FIG. 1. The resin sealed type semiconductor device according to the first preferred embodiment of the present invention comprises a semiconductor chip 201, a plurality of posts 202, a plurality of solder bumps 203, a plurality of re-tribute 204, a sealing resin 205, a plurality of pads 206, a radiation post 207 and an insulating film 208. As illustrated in FIG. 1, two solder bumps 203 are located at both sides of the radiation post 207. However, owing to an explanatory circumstance, the number of the pads, the re-tributes, the posts and the solder bumps is limited in FIG. 2.

[0036] The semiconductor chip 201 has a main surface 201 a. The circuits such as a transistor etc. are formed on the main surface 201 a of the semiconductor chip 201.

[0037] The pads 206 which are preferably made of aluminum or the like, and are formed on the main surface 201 a of the semiconductor chip 201.

[0038] The insulating film 208 is formed on the main surface 201 a of the semiconductor chip 201 and on a partial surface of the pads 206. The insulating film 208 protects the main surface 201 a.

[0039] The re-tributes 204 which are preferably made of copper, aluminum or titanium or the like, and are formed on the pads 206 and on the insulating film 208. The re-tributes 204 are electrically connected to the pads 206. The re-tribute 204 is an interconnection in order to freely adjust a position of the post 202 formed on thereof. Therefore, the posts 202 can be formed on any position which is not on the pads 206, in addition to on the pads 206.

[0040] The posts 202 are preferably made of copper or aluminum or the like, and each one has a first end side 202 a and a second end side 202 b. As mentioned above, the posts 202 are formed on the re-tributes 204, and are electrically connected to the re-tributes 204. The second end side 202 b is the opposite side of the re-tributes 204.

[0041] The solder bumps 203 which have the spherical shape, and are preferably made of solder, and each one is mounted on the first end side 202 a of the post 202. The solder bumps 203 are electrically connected to the posts 202. As a result, the pads 206, the re-tributes 204, the posts 202 and the solder bumps 203 are electrically connected to one another.

[0042] The radiation post 207 which is preferably made of copper or aluminum or the like, and is formed at the center position of the main surface 201 a of the semiconductor chip 201. The radiation post 207 has a main surface 207 a and a back surface 207 b. The main surface 207 a of the radiation post 207 is exposed to the outside of the sealing resin 205 and the back surface 207 b of the radiation post 207 is contacted with the insulating film 208.

[0043] It is desirable that the radiation post 207 is formed so as not to contact with the posts 202, the pads 206 or the re-tributes 204. If the radiation post 207 is contacted with the posts 202, this contact causes the posts 202 to electrically connect to each other, but it has nothing to do with a role as a radiation post. Therefore, there is a possibility that the posts 202 have a state of short-circuit. Thus, this means that the posts 202 do not lose a function as the electrode. The function of the re-tributes 204 and the pads 206 are also the same as that explained above.

[0044] The sealing resin 205 which is preferably made of epoxy resin or the like, and seals the posts 202, the re-tributes 204, the radiation post 207 and the insulating film 208. The main surface 207 a of the radiation post 207 is exposed to the outside of the sealing resin 205.

[0045] The radiation passes of the resin sealed type semiconductor device according to a first preferred embodiment of the present invention will be described with reference to FIG. 3. FIG. 3 is a cross sectional view showing radiation passes of a resin sealed type semiconductor device according to a first preferred embodiment. The resin sealed type semiconductor device is connected to a substrate 301 via the solder bumps 203. The arrows shown in FIG. 3 designate the routes conducting the heat that occurres in the semiconductor chip 201. As shown in FIG. 3, the heat occurred in the semiconductor chip 201 is radiated to the outside of the semiconductor chip 201 via the back and side surfaces of the semiconductor chip 201. In addition, the heat near the main surface 201 a of the semiconductor chip 201 is conducted to the substrate 301 via the posts 202 and the solder bumps 203, and thus the heat is radiated to the outside of the resin sealed type semiconductor device. Furthermore, the heat near the main surface 201 a of the semiconductor chip 201 is radiated to an area which exists between the resin sealed type semiconductor device according to the first preferred embodiment and the substrate 301 via the radiation post 207.

[0046] The resin sealed type semiconductor device according to the first preferred embodiment of the present invention is capable of radiating the heat occurred in the semiconductor chip 201 to its outside by using the posts 202, the solder bumps 203 and the radiation post 207. Therefore, the resin sealed type semiconductor device according to the first preferred embodiment of the present invention is capable of radiating the heat efficiently as compared with the conventional resin sealed type semiconductor device. Thus, the resin sealed type semiconductor device according to the first preferred embodiment of the present invention is capable of reducing thermal resistance and controlling high temperature of the semiconductor chip as compared with the conventional resin sealed type semiconductor device. As a result, the resin sealed type semiconductor device according to the first preferred embodiment having a longer lifetime can be obtained.

[0047] The process of manufacturing the resin sealed type semiconductor device according to the first preferred embodiment of the present invention will be described with reference to FIGS. 4A-4D and 5A-5D. The drawings are the schematic enlarged sectional views a part of the wafer.

[0048] First, as shown in FIG. 4A, the wafer (the semiconductor chip) 201 having the main surface 201 a on which a circuit such as a transistor or the like is formed, is prepared. The pads 206 are formed on the main surface 201 a of the wafer 201. The re-tributes 204 which are electrically connected to the pads 206, are formed on the pads 206 and the insulating film 208. The insulating film 208 is formed on the main surface 201 a, except for an area on which the re-tributes 204 are formed.

[0049] Next, as shown in FIG. 4B, a photosensitivity resin called as a photoresist film 401 is spin-coated on the insulating film 208 and the re-tributes 204. The film thickness of the photoresist film 401 needs height of the posts 202 and the radiation post 207 to be formed as the following steps.

[0050] Next, as shown in FIG. 4C, the photoresist film 401 is masked, and the masked photoresist film 401 is lithographed in order to expose a part of the re-tributes 204 and the insulating film 208. The size of the mask is set to the size of the posts 202 and the radiation post 207. The exposed photoresist film 401 is developed, and thus openings are formed in the photoresist film 401.

[0051] Next, as shown in FIG. 4D, the wafer with the photoresist film 401 having the openings, is soaked in a plating liquid and thus the openings are filled with the plating liquid. A kind of the plating liquid depends on the material of the posts 202 and the radiation post 207. If the posts 202 and the radiation post 207 are made of copper or aluminum, a copper plating liquid and an aluminum plating liquid are used.

[0052] Next, as shown in FIG. 5A, after the plating liquid becomes a solid state, the photoresist film 401 is removed from the wafer. Thereby, the posts 202 and the radiation post 207 are obtained.

[0053] Next, as shown in FIG. 5B, the posts 202, the re-tributes 204, the radiation post 207 and the insulating film 208 are sealed with the sealing resin 205 by using transfer-mold method or potting method or the like.

[0054] Next, as shown in FIG. 5C, the entire surface of the sealing resin 205 is etched or grinded. As a result, the first end sides 202 a of the posts 202 and the main surfaces 207 a of the radiation post 207 are exposed.

[0055] Next, as shown in FIG. 5D, the solder bumps 203 are mounted on the first end sides 202 a of the posts 202 by using the screen-printing method, the solder-plating method or the super-soldering method or the like.

[0056] In the process of manufacturing the resin sealed type semiconductor device according to the first preferred embodiment of the present invention, the radiation post 207 can be formed simultaneously in the process of forming the posts 202. Therefore, any special processes do not need to form the radiation post 207. Thus, the processes can be performed efficiently.

[0057] In FIGS. 1-2, owing to the explanatory circumstances, the number of the posts 202, the solder bumps 203, the re-tributes 204 and the pad 206-is limited to the specific number, i.e. two. However, even if the above number is changed, the resin sealed type semiconductor device according to the first preferred embodiment of the present invention is capable of getting the same effect.

[0058] (Second Embodiment)

[0059] A resin sealed type semiconductor device according to a second preferred embodiment of the present invention will be described with reference to FIGS. 6-8.

[0060] Frist, the composition of the resin sealed type semiconductor device according to the second preferred embodiment will be described with reference to FIGS. 6-7. FIG. 6 is a plane view showing the resin sealed type semiconductor device having a wafer level chip size package structure individually divided from a wafer. FIG. 7 is a cross sectional view taken line C-C of the semiconductor device shown in FIG. 6. Like elements are given like or corresponding reference numerals in the first and second preferred embodiments. Thus, dual explanations of the same elements are avoided. The resin sealed type semiconductor device according to the second preferred embodiment of the present invention comprises a semiconductor chip 201, a plurality of posts 202, a plurality of solder bumps 203, a plurality of re-tribute 204, a sealing resin 205, a plurality of pads 206, a radiation post 207, an insulating film 208 and a plurality of radiation bumps 701. As illustrated in FIG. 6, two solder bumps 203 are located at both sides of the radiation bumps 701. However, owing to an explanatory circumstance, the number of the pads, the re-tributes, the posts and the solder bumps is limited in FIG. 7.

[0061] The difference between the first and the second preferred embodiments is that the radiation bumps 701 are mounted on the main surface 207 a of the radiation post 207.

[0062] The radiation bumps 701 which have the spherical shape, and are preferably made of solder, and each one is mounted on the main surface 207 a of the radiation post 207.

[0063] The radiation passes of the resin sealed type semiconductor device according to the second preferred embodiment of the present invention will be described with reference to FIG. 8. FIG. 8 is a cross sectional view showing radiation passes of a resin sealed type semiconductor device according to the second preferred embodiment. The resin sealed type semiconductor device is connected to a substrate 801 via the solder bumps 203 and the radiation bumps 701. The arrows shown in FIG. 8 designate the routes conducting the heat occurred in the semiconductor chip 201. As shown in FIG. 8, the heat occurred in the semiconductor chip 201 is radiated to the outside of the semiconductor chip 201 via the back and side surfaces of the semiconductor chip 201. In addition, the heat near the main surface 201 a of the semiconductor chip 201 is conducted to the substrate 801 via the posts 202 and the solder bumps 203, and thus the heat is radiated to the outside of the resin sealed type semiconductor device. Furthermore, the heat near the main surface 201 a of the semiconductor chip 201 is radiated to an area which exists between the resin sealed type semiconductor device according to the second preferred embodiment and the substrate 801 via the radiation post 207. Furthermore, the heat near the main surface 201 a of the semiconductor chip 201 is conducted to the substrate 801 via the radiation posts 207 and the radiation bumps 701.

[0064] The resin sealed type semiconductor device according to the second preferred embodiment of the present invention is capable of radiating the heat occurred in the semiconductor chip 201 to its outside by using the posts 202, the solder bumps 203 and the radiation post 207. Therefore, the resin sealed type semiconductor device according to the second preferred embodiment of the present invention is capable of radiating the heat efficiently as compared with the conventional resin sealed type semiconductor device. Thus, the resin sealed type semiconductor device according to the second preferred embodiment of the present invention is capable of reducing thermal resistance and controlling high temperature of the semiconductor chip as compared with the conventional resin sealed type semiconductor device. As a result, the resin sealed type semiconductor device according to the second preferred embodiment having a longer lifetime can be obtained.

[0065] Furthermore, the resin sealed type semiconductor device according to the second preferred embodiment of the present invention has the radiation passes radiating the heat to its outside by using the radiation bumps 701. Thus, the resin sealed type semiconductor device according to the second preferred embodiment of the present invention is capable of reducing thermal resistance and controlling high temperature of the semiconductor chip as compared with the conventional resin sealed type semiconductor device. As a result, the resin sealed type semiconductor device according to the second preferred embodiment having a longer lifetime can be obtained.

[0066] The process of manufacturing the resin sealed type semiconductor device according to the second preferred embodiment of the present invention will be described with reference to FIGS. 4A-4D and 5A-5C. The drawings are the schematic enlarged sectional views a part of the wafer. All processes from a process of preparing the wafer 201 (refer to FIG. 4A) to a process of exposing the first end sides 202 a of the posts 202 and the main surface 207 a of the radiation post 207 (refer to FIG. 5C), are the same as those of the second embodiment.

[0067] The difference between the first and the second preferred embodiments is that the radiation bumps 701 are mounted on the main surface 207 a of the radiation post 207 during the process shown in FIG. 5D. In detail, the solder bumps 203 and the radiation bumps 701 are mounted on the first end sides 202 a of the posts 202 and the main surface 207 a of the radiation post 207, respectively, by using the screen-printing method, the solder-plating method or the super-soldering method, etc.

[0068] In the process of manufacturing the resin sealed type semiconductor device according to the second preferred embodiment of the present invention, the radiation bumps 701 can be formed simultaneously in the process of forming the solder bumps 203. Therefore, any special processes do not need to form the radiation bumps 701. Thus, the processes can be performed efficiently.

[0069] In FIGS. 6-7, owing to the explanatory circumstances, the number of the posts 202, the solder bumps 203, the re-tributes 204, the pad 206 and the radiation bumps 701 is limited to the specific number, i.e. two. However, even if the above number is changed, the resin sealed type semiconductor device according to the second preferred embodiment of the present invention is capable of getting the same effect.

[0070] (Third Embodiment)

[0071] A resin sealed type semiconductor device according to a third preferred embodiment of the present invention will be described with reference to FIGS. 9-10.

[0072] Frist, the composition of the resin sealed type semiconductor device according to the third preferred embodiment will be described with reference to FIG. 9. FIG. 9 is a cross sectional view showing the resin sealed type semiconductor device according to the third preferred embodiment. Like elements are given like or corresponding reference numerals in the first, second and third preferred embodiments. Thus, dual explanations of the same elements are avoided. The resin sealed type semiconductor device according to the third preferred embodiment of the present invention comprises a semiconductor chip 201, a plurality of posts 202, a plurality of solder bumps 203, a plurality of re-tribute 204, a sealing resin 205, a plurality of pads 206, a radiation post 207, an insulating film 208, a plurality of radiation bumps 701 and a solder resist layer 901. Owing to an explanatory circumstance, the number of the pads, the re-tributes, the posts and the solder bumps is limited in FIG. 9.

[0073] The difference among the first, the second and the third preferred embodiments is that the solder resist layer 901 is formed on the surface of the sealing resin 205 and the main surface 207 a of the radiation post 207.

[0074] The resin sealed type semiconductor device according to the third preferred embodiment of the present invention is capable of radiating the heat occurred in the semiconductor chip 201 to its outside by using the posts 202, the solder bumps 203, the radiation post 207 and the radiation bumps 701. Therefore, the resin sealed type semiconductor device according to the third preferred embodiment of the present invention is capable of radiating the heat efficiently as compared with the conventional resin sealed type semiconductor device. Thus, the resin sealed type semiconductor device according to the third preferred embodiment of the present invention is capable of reducing thermal resistance and controlling high temperature of the semiconductor chip as compared with the conventional resin sealed type semiconductor device. As a result, the resin sealed type semiconductor device according to the third preferred embodiment having a longer lifetime can be obtained. Although the solder resist layer 901 is formed on the surface of the sealing resin 205 and the main surface 207 a of the radiation post 207, it goes without saying that the radiation efficiency of the heart occurred in the semiconductor chip 201 is not inferior to the conventional resin sealed type semiconductor.

[0075] Furthermore, the resin sealed type semiconductor device of the third embodiment of the present invention has the solder resist layer 901. Thus, the solder bumps 203 and the radiation bumps 701 can be stably mounted on the posts 202 and the radiation posts 207, respectively. Even if the size of the solder bumps 203 differ from of the radiation bumps 701, the solder bumps 203 and the radiation bumps 701 can be stably mounted on the posts 202 and the radiation posts 701, respectively, due to the solder resist layer 901. Therefore, the solder bumps 203 and the radiation bumps 701 can be mounted at the same process. Any special processes do not need to form the radiation bumps 701. Thus, the processes can be performed efficiently.

[0076] The process of manufacturing the resin sealed type semiconductor device according to the third preferred embodiment of the present invention will be described with reference to FIGS. 10A-10C. The drawings are the schematic enlarged sectional views a part of the wafer. In the following explanations, the solder resist having a photosensitive property is explained as an example of the solder resist layer 901. However, the solder resist layer 901 should not be limited to the photosensitive solder resist. All processes from a process of preparing the wafer 201. (refer to FIG. 4A) to a process of exposing the first end sides 202 a of the posts 202 and the main surface 207 a of the radiation post 207 (refer to FIG. 5C), are the same as those of the third embodiment.

[0077] The difference among the first, the second and the third preferred embodiments is that the processes shown in FIGS. 10A-10C are performed instead of the process shown in FIG. 5D. After the process shown in FIG. 5C has been performed, as shown in FIG. 10A, the photosensitive solder resist 901 is spin-coated on the surface of the sealing resin 205, the first end side 202 a of the post 202 and the main surface 207 a of the radiation post 207, then the spin-coated photosensitive solder resist 901 is temporarily dried.

[0078] Next, as shown in FIG. 10B, the temporarily dried solder resist layer 901 is masked, and the masked solder resist layer 901 is lithographed in order to expose a part of the first end sides 202 a of the posts 202 and a part of the main surfaces 207 a of the radiation posts 701. The size of the mask is set to the size of the solder bumps 203 and the radiation bumps 701. The exposed solder resist layer 901 is developed, and thus openings are formed in the solder resist layer 901.

[0079] Next, as shown in FIG. 10(c), the solder bumps 203 and the radiation bumps 701 are mounted on the exposed first end sides 202 a of the posts 202 and the exposed main surfaces 207 a of the radiation posts 701 by using the screen-printing method, the solder-plating method or the super-soldering method, etc.

[0080] In the process of manufacturing the resin sealed type semiconductor device according to the third preferred embodiment of the present invention, the radiation bumps 701 can be formed simultaneously in the process of forming the solder bumps 203, even if there is a difference between the sizes of the solder bumps 203 and the radiation bumps 701. Therefore, any special processes do not need to form the radiation bumps 701. Thus, the processes can be performed efficiently.

[0081] In FIGS. 9-10, owing to the explanatory circumstances, the number of the posts 202, the solder bumps 203, the re-tributes 204, the pad 206 and the radiation bumps 701 is limited to the specific number, i.e. two. However, even if the above number is changed, the resin sealed type semiconductor device according to the third preferred embodiment of the present invention is capable of getting the same effect.

[0082] (Fourth Embodiment)

[0083] A resin sealed type semiconductor device according to a fourth preferred embodiment of the present invention will be described with reference to FIGS. 11A-11B.

[0084]FIG. 11 describes the arrangement relationship between the radiation posts 207 or the solder bumps 203. As shown in FIG. 11, the radiation posts 207 of the fourth embodiment of the present invention is formed at the various positions over the main surface 201 a of the semiconductor chip 201. FIG. 11 does not show the radiation bumps 701 which are formed on the radiation posts 207. However, it is clear that the radiation bumps 701 are mounted on the radiation posts 207 as the above mentioned in the first and the second embodiments of the present invention.

[0085] In FIG. 11A, the radiation posts 207 are formed at the edge area of the semiconductor chip 201. If the radiation posts 207 can not be formed at the central area of the semiconductor chip 201, the resin sealed type semiconductor device shown in FIG. 11A becomes effective.

[0086] In FIG. 11B, the radiation posts 207 are formed around specific solder bumps 203. The resin sealed type semiconductor device is suitable for radiating the heat of the specific solder bumps 203 which are highly required to radiate the heat.

[0087] The resin sealed type semiconductor device according to the fourth preferred embodiment of the present invention is capable of radiating the heat occurred in the semiconductor chip 201 to its outside by using the posts 202, the solder bumps 203, the radiation post 207 and the radiation bumps 701. Therefore, the resin sealed type semiconductor device according to the fourth preferred embodiment of the present invention is capable of radiating the heat efficiently as compared with the conventional resin sealed type semiconductor device. Thus, the resin sealed type semiconductor device according to the fourth preferred embodiment of the present invention is capable of reducing thermal resistance and controlling high temperature of the semiconductor chip as compared with the conventional resin sealed type semiconductor device. As a result, the resin sealed type semiconductor device according to the fourth preferred embodiment having a longer lifetime can be obtained.

[0088] While the preferred form of the present invention has been described, it is to be understood that modifications will be apparent to those skilled in the art without departing from the spirit of the invention.

[0089] The scope of the invention, therefore, is to be determined solely by the following claims. 

What is claimed is:
 1. A semiconductor device, comprising: a semiconductor chip which has a pad formed on a main surface thereof; an insulating film which is formed on a part of said pad and on said main surface of said semiconductor chip; an interconnection which is formed on a part of said insulating film and which is electrically connected to said pad; a sealing resin which seals said interconnection and said insulating film; a post formed on said interconnection which has a surface exposed to outside of said sealing resin which is electrically connected to said interconnection; a bump electrode which is mounted on said exposed surface of said post; and a radiation post which is formed on said insulating film and which has a surface exposed to outside of said sealing resin.
 2. The semiconductor device in accordance with claim 1, said semiconductor device further comprising; a radiation bump unit which is formed on said exposed surface of said radiation post.
 3. The semiconductor device in accordance with claim 2, wherein said radiation bump is spherical shape.
 4. The semiconductor device in accordance with claim 1, wherein said radiation post which is provided over the center of said main surface of said semiconductor chip; and said post which is provided over the periphery of said main surface of said semiconductor chip.
 5. The semiconductor device in accordance with claim 4, said semiconductor device further comprising; a radiation bump which is formed on said exposed surface of said radiation post.
 6. The semiconductor device in accordance with claim 1, wherein said radiation post is provided at the outermost of said main surface of said semiconductor chip.
 7. The semiconductor device in accordance with claim 6, said semiconductor device further comprising; a radiation bump which is formed on said exposed surface of said radiation post.
 8. The semiconductor device in accordance with claim 7, wherein said radiation bump is spherical shape.
 9. The semiconductor device in accordance with claim 1, wherein said radiation post is provided around said solder bump.
 10. The semiconductor device in accordance with claim 9, said semiconductor device further comprising; a radiation bump which is formed on said exposed surface of said radiation post.
 11. The semiconductor device in accordance with claim 10, wherein said radiation bump is spherical shape.
 12. A method of manufacturing a semiconductor device, said method including: providing a wafer having a main surface on which a pad is formed; forming an insulating film on a part of said pad and on said main surface of said wafer; forming an interconnection on a part of said insulating film to connect to said pad; providing a resist film having first and second openings to expose portions of said insulating film and said interconnection; filling said first and second openings with a plating liquid to form a post and a radiation post in said first and second openings respectively; removing said resist film; and sealing said interconnection, said insulating film and side surfaces of said post and said radiation post.
 13. The method of claim 12, said method further comprising: removing said sealing resin until top surfaces of said post and said radiation post are exposed.
 14. The method of claim 12, said method further comprising: forming a radiation bump on top surface of said radiation post. 